The first full day of US President Donald Trump's state visit to the UK has begun.
King Charles and Queen Camilla welcomed US President Donald Trump and his wife Melania to the UK as Mr Trump's historic second state visit got under way.
The American leader and First Lady were treated to a personal, family-centred greeting outside Victoria House, a little-known property nestled in the Royal Kitchen Gardens at Frogmore on the private Windsor estate.
Prince William and Princess Kate were deployed at the start of the royal charm offensive to greet the Trumps who arrived in Marine One, the call sign of the United States Marine Corps aircraft carrying the president.
The state-of-the-art presidential helicopter, fitted with missile defence and radar jamming systems, landed on the lawn of the vast Walled Garden in the Berkshire grounds shortly after midday.
The king arrived with the queen in the state Bentley before heading inside Victoria House.
The timings were slightly behind schedule with Mr Trump arriving at 12.14pm, behind the planned time of 11.55am.
The prince and princess escorted the president and his wife the short walking distance to meet the king and queen in front of the gable-ended Victoria House.
The unique setting, never used before during an incoming state visit in modern times, is just one of a number of flourishes being added to impress the controversial billionaire-turned politician, who sees the king as his "friend".
Queen Camilla rallied to attend the first engagement of the key diplomatic royal duty after pulling out of the Duchess of Kent's funeral yesterday due to acute sinusitis.
Pomp and pageantry was out in full force with the scale and spectacle of the military ceremonial on show for Mr Trump unprecedented.
Lining the carriage procession route through the private Windsor estate to the castle were 22 half-companies of personnel from throughout the Royal Navy, the Royal Marines, the British Army and the Royal Air Force.
The Trumps were joining the king and queen and the prince and princess for the scenic carriage ride through the green parkland to the castle, accompanied by a colourful Sovereign's Escort of the Life Guards and the Blues and Royals of the Household Cavalry Mounted Regiment.
Some 120 horses and 1,300 members of the British military are involved in the ceremonial welcome at Windsor, with 160 personnel from the Royal Marines and Royal Navy, 1,000 from the British Army and 140 from the Royal Air Force.
The formal ceremonial welcome in the castle quadrangle features the largest ever Guard of Honour for this occasion.
As the king shook hands with Mr Trump at Victoria House, royal gun salutes were simultaneously fired from six First World War era guns on the East Lawn of Windsor Castle and at the Tower of London.
There are no public-facing elements during Mr Trump's engagements, with security paramount for the 47th US president - who has faced two assassination attempts in just over a year - in the wake of the killing of his US ally Charlie Kirk.
Mr Trump has previously hinted at possible tariff relief for UK steel ahead of talks with UK Prime Minister Keir Starmer at his country residence, Chequers, tomorrow.
Both leaders are likely to discuss a range of matters including trade.
Other elements of the royal-focused first day include a visit to the tomb of Queen Elizabeth II in St George's Chapel, lunch with the royal family, a special Beating Retreat ceremony with a flypast of UK and US F-35 fighter jets and the Red Arrows, and in the evening, a lavish state banquet.
Gifts
The Trumps will give the king a replica of a President Eisenhower Sword in a gift exchange.
It symbolises "profound respect" and acts as a "reminder of the historical partnership that was critical" to winning the Second World War, according to Buckingham Palace.
"The sword also symbolises the enduring values and co-operative spirit that continues to define the relationship between the United States and Great Britain," the palace added.
The king and queen also have presents for their American guests.
They will gift Mr Trump a bespoke, hand-bound leather book specially crafted by the Royal Bindery in Windsor Castle to celebrate the 250th anniversary of the Declaration of Independence, which was adopted in Philadelphia on 4 July, 1776.
They will also gift him the union flag that was hoisted above Buckingham Palace on the day of the president's inauguration earlier this year.
Ms Trump is due to receive a silver and enamel bowl featuring the queen's cypher crafted by Northern Irish artist Cara Murphy, a renowned silversmith who has created works for Downing Street and the Grand National.
The First Lady will also receive a personalised Anya Hindmarch handbag.
The royals will give the American couple a silver photograph frame engraved with their joint cyphers.
Meanwhile the queen will be gifted a Tiffany & Co vintage 18-carat gold, diamond and ruby flower brooch.
The brooch, said to represent diplomacy, friendship, and respect, features the queen#s birthstone - rubies - and that of Ms Trump's - diamonds.
The Trumps will stay overnight in the castle as guests of the king and queen.
The Trumps arrived at Stansted Airport last night, before making their way on board Marine One helicopter to central London, where they spent the night.
Mr Trump stayed last night at the US Ambassador's residence at Regents Park in London.
Upon arriving in the UK, Mr Trump spoke of his love for the country, telling reporters that it was a "great honour" to be hosted by his "friend", the king.
Meanwhile, four people were arrested after giant images of Donald Trump and the convicted sex offender Jeffrey Epstein were projected onto the walls of Windsor Castle.
Thousands are taking part in major protests against his two-day stay, with a march through central London, followed by a rally in Parliament Square.
Campaigners from as many as 50 groups are taking part in the action.
Officers at the protest said according to the latest estimates there are at least 3,000 people in the march.
One counter protester who earlier left crowds of anti-Trump campaigners surrounded by police sat at Oxford Circus with a sign saying "We Love Trump" and was greeted with boos as anti-Trump campaigners marched past him.
The individual protester chanted "We Love Trump" and was surrounded by police officers.
Watch: Protesters rally outside Windsor Castle ahead of Trump's state visit
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Additional reporting: PA
